In pressure vessels, in particular compressor housings, temperature differences between various modules of the pressure vessel frequently occur, in particular in non-steady-state operation. For example, in the case of a high pressure turbocompressor, a substantially cylindrical main housing can be closed on the end side by means of a cover which is preferably arranged at least partially in an axial overlap in the pressure container. As a consequence of temperature differences, a radial thermal relative expansion occurs between the end-side cover and the at least partially encapsulating housing main body, for which corresponding movement plays have to be provided. In addition, temperature differences between the described housing components have to be maintained deliberately even in steady-state operation, in order that boundary conditions for other components are met. For example, gas seals have to be operated in a comparatively narrow temperature range, with the result that, in refrigeration engineering, temperatures of below −100° C. make it necessary to heat the gas seal, in order for it to be possible to operate the gas seal in the allowable range. At least in the region of the axial overlap between the cover and the housing jacket with regard to the machine axis which extends in the longitudinal direction along a rotor, radial plays which are dependent on the external diameter of the cover of, for example, 2 mm/1000 mm external diameter of the cover have to be provided. The very recent trend toward ever larger compressor designs leads to plays which can no longer be sealed by means of conventional static seals, because the latter are destroyed in the gaps at the prevailing pressures and the size of the gaps to be sealed.